package Date1206;

public class Demo1 {
    public static void main(String[] args) {
        for (int i = 1; i < 1000000007; i++)
        {
            if ((i * 2021) % 1000000007 == 999999999)
            {
                System.out.println(i);
                return;
            }
        }
        System.out.println(0);
    }

    
}
